Ergodic Capacity Analysis of MIMO NOMA Systems under Rayleigh and Rician Fading Channels

This paper presents a detailed analysis of ergodic capacity for Multiple-Input Multiple-Output (MIMO) Non-Orthogonal Multiple Access (NOMA) systems under Rayleigh and Rician fading channels. The MATLAB simulations are used to study the impact of fading conditions on ergodic capacity across various user positions, denoted by K. The key observation from our results is that, under both fading models, the ergodic capacity grows linearly with increasing Signal-to-Interference-plus-Noise Ratio (SINR), where always a tiny advantage is taken by Rician fading channels over the Rayleigh ones because of the existence of a line-of-sight (LOS) component. This work brings to the forefront, through performance simulation, the importance of channel conditions in designing for optimum system performance and offers valuable insights into realizable system design and deployment under various environmental contexts. It was determined that adaptive techniques, combined with strategic deployment, would significantly change network efficiency and user experience, particularly in environments favoring LOS signal propagation.